534 STUART WELLER 



mens usually preserve the cast of the basal portion of the axial 

 canal where it enters the radial plate. The species differs from 

 C. cora, especially in the strong constriction of the calyx at its 

 middle line. 



In the light of the observations here recorded, the synonomy 

 of Crotalocrinus cora will stand as follows : 



Crotalocrinus cora (Hall). 



1868. Cyathocrinus cora Hall, Twentieth Rep. N. Y. State Cad. Nat. 



Hist., p. 324, PI. XI, Figs. 13, 14. 

 1870. Cyathocrinus cora Hall Twentieth Rep. N. Y. State Cab. Nat. 



Hist. (Rev. Ed.), p. 366, PI. XI, Figs. 13, 14. 

 1879. Cyathocrinus cora W. & S., Rev. Palceocr., Pt. I, p. 85. 

 1 88 1. Cyathocrinus cora S. A. M., Jour. Cinn. Soc. Nat. Hist., Vol. IV, 



p. 171. 

 1900. Cyathocrinus cora Weller, Bull. No. 4. Nat. Hist. Surv., Chicago 



Acad. Sci., p. 62, PL XIV, Figs. 6-10. 

 1900. Crotalocrinus americanus Weller, Bull. No. 4., Nat. Hist. Surv., 



Chicago Acad. Sci., p. 143, PI. XIV, Fig. 1. 



EXPLANATION OF PLATE. 



Fig. 1. — A nearly perfect specimen of the calyx of Crotalocrinus cora 

 showing the plates of the calyx with some of the brachial plates. 



Fig. 2. — An internal cast of Crotalocrinus cora, showing the broken bases 

 of the casts of the axial canals where they pierce the radial plates. 



Fig. 3. — An outline of the specimen which was made the type of Crotalo- 

 crinus americanus, showing the arrangement of the fixed brachial plates in 

 Crotalocrinus cora. 



Figs. 4-5. — The casts of two radial plates of Crotalocrinus cora, preserv- 

 ing the internal casts of the axial canals. 



Stuart Weller. 



